Performance of 3rd Generation Locally Available Chemical Admixtures in the Production of SCC

M. Yousaf, Z.A. Siddiqi, B. Sharif, A. H. Khan

Abstract


Increasing trend in urbanization and industrialization has necessitated production of high rise buildings with an innovation to make an optimized use of reduced available land in thickly populated areas, which is not possible by standard conventional concrete. Such a different concrete can be created only through different types of admixtures, which when added at various stages of concrete production yield required properties without scarifying the durability and economy of the structure. A proper mix design of self-compacting concrete (SCC) gives improved properties required in fresh state as well as in hardened state thus enhancing the durability of the structure through good bonding between concrete and steel apart from other factors. Present paper gives an outline of the fundamental rheological properties such as flow-ability, passing-ability and stability of self -compacting concrete in fresh state using variety of the locally available chemical admixtures related to 1st, 2nd and 3 rdgenerations from various chemicals supplying outlets. ASTM-test methods along with ACI, EFNARC and RILEM specifications and guidelines were followed throughout the experimentation process. It was observed that 3rd generation chemical admixtures gave better performance compared to 1 st and 2nd generation admixtures. Flow-ability and passing-ability for the produced concrete were found to be improved by an average of more than 25%. SCC produced was highly stable showing improvement in compressive strength by average of 30%. All this can be attributed to the long chain molecular structure of the Poly-Carboxylate Ether (PCE)in 3rd generation chemical admixtures helping produce highly fluid yet a stable concrete.

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References


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